As our ability to explore Mars increases,
we need to create a capable communications system that will support
global reconnaissance of the planet. This infrastructure will also relay
back to Earth the vast amounts of information gathered through surface
exploration, sample return missions, robotic outposts and even
eventual human exploration.

Each future science orbiter,
including the Mars Reconnaissance Orbiter,
will continue to carry a proximity communications system for relaying
information from surface and aerial vehicles. Science orbiters, however,
typically orbit as close as possible to Mars, receiving communication
from surface vehicles in brief spurts only when passing rapidly across
the sky. To provide more constant relays, a dedicated communications
orbiter is being jointly planned by NASA and the Italian Space Agency to
orbit at several thousand kilometers altitude in 2007.

Each science and communications
orbiter can also be used to accurately determine the position and
velocity of spacecraft approaching Mars, landers descending to the
surface and vehicles moving around on the surface and in the
atmosphere. Advances in radio navigation are needed to fully exploit
the potential for in situ exploration of Mars.

Technologies needed for Mars
exploration include higher frequency K band radios for communications
between orbiters, large landed assets and Earth. Lightweight antennas
are also needed for improving communication rates. Further down the
road, optical communications offer the potential for very high data
rates using compact communications packages.

As the number of assets on the Mars
surface grows, we anticipate communications would occur using an
Internet Protocol similar to the one we have now on Earth.
Achievement of this goal would mean the establishment of the
first Interplanetary Internet!